50+ Genetic Engineering MCQ with Answers
50+ Genetic Engineering MCQ with Answers
Q1. Which of the following is not a genetic engineering tool?
A) Restriction endonucleases
B) DNA polymerase
C) DNA ligase
D) Carrier
Correct Answer: B
Explanation: DNA polymerase is used for replication, not specifically for genetic manipulation like cutting or ligating DNA.
Q2. Which of the following are often used to carry genes of interest in genetic engineering?
A) Bacterial plasmids
B) Bacteriophage
C) Both of these
D) All of these
Correct Answer: C
Explanation: Both plasmids and bacteriophages are commonly used vectors in recombinant DNA technology.
Q3. Which of the following cannot be used as vectors in genetic engineering?
A) Bacterial plasmids
B) Bacteriophage
C) Bacterial nucleoid DNA
D) Animal and plant viruses
Correct Answer: C
Explanation: The bacterial nucleoid contains essential genes and cannot serve as a vector for cloning.
Q4. “Molecular scissors” used in genetic engineering is
A) DNA polymerase
B) DNA ligase
C) Restriction endonuclease
D) Helicase
Correct Answer: C
Explanation: Restriction enzymes cut DNA at specific sequences, earning the name “molecular scissors.”
Q5. Which of the following is related to genetic engineering?
A) Plasmid
B) Heterosis
C) Mutation
D) Plastid
Correct Answer: A
Explanation: Plasmids are commonly used vectors to introduce foreign genes in genetic engineering.
Q6. The tool for cutting the target gene in genetic engineering is
A) DNA ligase
B) Helicase
C) DNA polymerase
D) Restriction endonuclease
Correct Answer: D
Explanation: Restriction endonucleases cleave DNA at specific sequences to isolate the target gene.
Q7. rDNA technology is known as
A) Genetic engineering
B) Genetic recombinant
C) Genetic improvement
D) None of the above
Correct Answer: A
Explanation: Recombinant DNA (rDNA) technology is a part of genetic engineering where genes are manipulated artificially.
Q8. Which of the following is not a tool of genetic engineering?
A) Cloning vector
B) Restriction enzyme
C) Foreign DNA
D) GMO
Correct Answer: D
Explanation: A genetically modified organism (GMO) is the product of genetic engineering, not a tool.
Q9. The ideal size of a cloning vector (plasmid) should be less than
A) 10 kb
B) 100 kb
C) 1000 kb
D) 1 MB
Correct Answer: A
Explanation: Efficient cloning requires small plasmids (under 10 kb) for easy replication and transfer.
Q10. DNA sequencing is carried out by
A) Maxam-Gilbert method
B) Sanger dideoxy method
C) Both A and B
D) Watson and Crick
Correct Answer: C
Explanation: Both the Maxam-Gilbert and Sanger methods are classical DNA sequencing techniques.
Q11. The enzymes commonly used in genetic engineering are
A) Endonuclease and ligase
B) Restriction endonuclease and polymerase
C) Ligase and polymerase
D) Restriction endonuclease and ligase
Correct Answer: D
Explanation: Restriction enzymes cut DNA and ligases join the fragments—both essential in rDNA techniques.
Q12. Which of the following statements are correct about plasmids?
A) They are circular DNA molecules
B) They replicate independently in bacterial cells
C) They carry one or more genes
D) All of these
Correct Answer: D
Explanation: Plasmids are circular, self-replicating DNA molecules carrying genes like antibiotic resistance.
Q13. The four steps of an rDNA experiment include
A) Generating DNA fragments
B) Joining DNA to vectors
C) Introducing into host cells
D) Selecting recipient cell clones
E) All of these
Correct Answer: E
Explanation: All listed steps are key stages in recombinant DNA experiments.
Q14. Which of the following statements about genetic engineering is true?
A) DNA polymerase is the “needle and thread”
B) Recipient cell is called carrier
C) Enables targeted interspecific gene recombination
D) GM food safety concerns mean research must stop
Correct Answer: C
Explanation: Genetic engineering allows for cross-species gene recombination to create desired traits.
Q15. Which of the following statements is true?
A) Ligases join nucleic acids
B) Polymerases make copies
C) Modifying enzymes alter chemical groups
D) All of these
Correct Answer: D
Explanation: Each statement defines key functions of enzymes used in genetic engineering.
Q16. Organisms whose genes are altered using genetic engineering are called
A) Genetically mutant organisms
B) Genetically modern organisms
C) Genetically modified organisms
D) Genetically transferred organisms
Correct Answer: C
Explanation: GMOs are organisms whose DNA has been modified using recombinant DNA technology.
Q17. Which of the following is used in genetic engineering?
A) Restriction endonuclease
B) Mycobacterium
C) Entamoeba
D) Pepsin
Correct Answer: A
Explanation: Restriction endonucleases are fundamental tools for cutting DNA in genetic engineering.
Q18. In genetic engineering, the enzyme that binds the gene to the carrier is
A) Helicase
B) RNA polymerase
C) DNA ligase
D) Restriction endonuclease
Correct Answer: C
Explanation: DNA ligase seals DNA fragments by forming phosphodiester bonds.
Q19. Widely used tool in plant genetic engineering is
A) Protoplast fusion
B) Transposon
C) Microinjection
D) Agrobacterium mediation
Correct Answer: D
Explanation: Agrobacterium tumefaciens is used to transfer genes into plant cells.
Q20. The organism whose genes are artificially altered is called
A) Genetically mutant organism
B) Gene transfer
C) Genetically modified organism
D) Genetically transferred organism
Correct Answer: C
Explanation: A GMO has artificially modified genes to achieve desired traits.
Q21. The first commercially grown genetically engineered crop was
A) Potato
B) Cotton
C) Maize
D) Tomato
Correct Answer: D
Explanation: The Flavr Savr tomato was the first genetically engineered crop approved for human consumption.
Q22. Genetic engineering was first commercially employed to
A) Develop human DNA using bacteria
B) Develop pest-resistant plants
C) Produce human insulin using bacteria
D) Increase crop yield
Correct Answer: C
Explanation: Human insulin was first produced commercially using genetically modified bacteria.
Q23. Which bacteria is extensively used in plant genetic engineering?
A) Agrobacterium tumefaciens
B) Clostridium septicum
C) Xanthomonas citri
D) Bacillus coagulans
Correct Answer: A
Explanation: Agrobacterium tumefaciens transfers foreign genes into plants via Ti plasmids.
Q24. Restriction endonucleases are used because
A) They degrade harmful proteins
B) They join DNA fragments
C) They cut DNA at specific sequences
D) They cut DNA at random sites
Correct Answer: C
Explanation: Restriction enzymes recognize and cut DNA at specific nucleotide sequences.
Q25. The ultimate goal of genetic engineering is to
A) Extract DNA
B) Cleave DNA
C) Modify DNA
D) Create genetically engineered organisms
Correct Answer: D
Explanation: The goal is to develop organisms with modified genomes for desired traits.
Q26. Which of the following are examples of transgenic crops?
A) Tobacco and cotton
B) Tomato and rice
C) Maize and sugarcane
D) Tomato and wheat
Correct Answer: A
Explanation: Bt cotton and genetically engineered tobacco are examples of pest-resistant transgenic crops.
Q27. Bacteria associated with plant genetic engineering include
A) Salmonella and Pseudomonas
B) Salmonella typhimurium and Agrobacterium
C) Bacillus thuringiensis and Pseudomonas fluorescens
D) Both B and C
Correct Answer: D
Explanation: Both Agrobacterium (gene transfer) and Bacillus thuringiensis (Bt toxin) are used in genetic engineering.
Q28. GEAC (Genetic Engineering Approval Committee) in India is for
A) Granting patents
B) Bio-resource protection
C) Validating GM safety
D) Fighting biopiracy
Correct Answer: C
Explanation: GEAC evaluates research and safety aspects of genetically modified organisms.
Q29. Human protein production in bacteria is possible because
A) RNA splicing occurs in bacteria
B) Human chromosomes replicate in bacteria
C) Gene regulation is the same in both
D) Genetic code is universal
Correct Answer: D
Explanation: All living organisms use the same genetic code, enabling gene expression across species.
Q30. Genetic engineering is possible because
A) Transduction is well understood
B) DNA is visible under electron microscope
C) We can cut DNA with enzymes
D) Restriction enzymes are purified from bacteria
Correct Answer: D
Explanation: Restriction enzymes isolated from bacteria are key tools enabling genetic manipulation.
Q31. The theories that led to genetic engineering are
A) Proof of DNA as genetic material
B) Discovery of tool enzymes
C) Establishment of DNA structure and central dogma
D) All of these
Correct Answer: D
Explanation: Each of these foundational discoveries paved the way for genetic engineering.
Q32. Which of the following statements is incorrect?
A) DNA ligase links DNA fragments
B) Plasmids are used as carriers
C) Plasmids replicate independently
D) Interferon mRNA from yeast proves target gene expression
Correct Answer: D
Explanation: Interferon expression is typically studied in E. coli or mammalian cells, not yeast.
Q33. Which statement about genetic engineering is true?
A) DNA polymerase is “needle and thread”
B) Recipient cell is called the carrier
C) Enables targeted interspecies gene recombination
D) GM food safety concerns mean research should stop
Correct Answer: C
Explanation: Genetic engineering allows precise transfer of genes across species barriers.
Q34. Which statement about gene expression vectors is incorrect?
A) Must be constructed within cells
B) Antibiotic resistance genes are markers
C) Terminators are at the gene’s end
D) Promoters are at the gene’s start
Correct Answer: A
Explanation: Gene vectors are usually constructed outside cells in vitro and then introduced.
Q35. In genetic engineering, restriction enzymes are mainly used to
A) Extract and introduce genes
B) Detect inserted genes
C) Bind and insert genes
D) Extract and bind genes to carriers
Correct Answer: D
Explanation: Restriction enzymes isolate and prepare target genes for insertion into vectors.
Q36. Which is true about T4 DNA ligase?
A) Isolated from E. coli
B) Only joins sticky ends
C) Only joins blunt ends
D) Joins both sticky and blunt ends
Correct Answer: D
Explanation: T4 DNA ligase can join both sticky and blunt ends during ligation.
Q37. Which statement is true?
A) Restriction enzymes only extract genes
B) Recombinant plasmids form inside cells
C) All plasmids can serve as carriers
D) Protein structure gives info for gene synthesis
Correct Answer: D
Explanation: Reverse translation can deduce gene sequences from known protein structures.
Q38. In genetic engineering, “scissors,” “needle and thread,” and “carrier” refer to
A) E. coli virus, plasmid, ligase
B) Phage, plasmid, ligase
C) Restriction enzyme, RNA ligase, plasmid
D) Restriction enzyme, DNA ligase, plasmid
Correct Answer: D
Explanation: These metaphors correspond to cutting (enzyme), joining (ligase), and transferring (plasmid).
Q39. Which of the following about plasmids is correct?
A) They are granular organelles
B) Small circular DNA molecules
C) Replicate only in host cells
D) Replication independent of host
Correct Answer: B
Explanation: Plasmids are small, circular, self-replicating DNA in bacterial cytoplasm.
Q40. Which statement about restriction enzymes is incorrect?
A) They catalyze hydrolysis
B) Affected by temperature and pH
C) Recognize specific sequences
D) Shorter recognition site = less frequent presence
Correct Answer: D
Explanation: Shorter recognition sequences occur more frequently in DNA, not less.
Q41. For target gene and vector cutting, the required condition is
A) Different enzymes, same sticky ends
B) Same enzymes, sticky ends may differ
C) Same enzymes, same sticky ends
D) Different enzymes, different sticky ends
Correct Answer: C
Explanation: Using the same enzyme ensures compatible sticky ends for ligation.
Q42. The gene of interest can be detected in recipient cells because
A) Gene is marked
B) Plasmid has marker genes
C) Plasmid replicates
D) None of these
Correct Answer: B
Explanation: Plasmids carry marker genes (e.g., antibiotic resistance) to identify successful insertion.
Q43. Which is correct?
A) Genetic engineering targets antibiotic resistance
B) Plasmids are common carriers
C) Different enzymes used for target and vector DNA
D) Only fertilized eggs are used in crops
Correct Answer: B
Explanation: Bacterial plasmids are standard vectors in most genetic engineering procedures.
Q44. The core step of genetic engineering is
A) Obtaining target gene
B) Constructing expression vector
C) Introducing gene
D) Detecting gene
Correct Answer: B
Explanation: The central step is building a vector that expresses the target gene properly.
Q45. Which is not a gene detection method?
A) Molecular hybridization
B) Antigen–antibody hybridization
C) Inoculation experiments
D) Gene gun
Correct Answer: D
Explanation: A gene gun is a delivery method, not a detection tool.
Q46. If gene base sequence is known, best way to obtain the gene is
A) Reverse transcription
B) Chemical synthesis
C) PCR
D) None of these
Correct Answer: C
Explanation: PCR (Polymerase Chain Reaction) amplifies known gene sequences efficiently.
Q47. Which statement about gene probes is incorrect?
A) Use base pairing
B) Target DNA must unwind
C) Direct sequencing with probe is possible
D) Used in diagnostics
Correct Answer: C
Explanation: Probes identify complementary sequences but do not sequence DNA directly.